Hours are no indicator of condition. A factory ovehauled engine built to 'as-new' limits can have a third run set of crankcases - 6000hrs and conrods and crank which could have been in action since the ark first floated.
Because the camshaft and valve gear is poorly designed it will almost certainly be new. The rest? Could be almost any age. What this tells you is that hours run are almost irrelevent. Condtion is everything.
Cylinders? Good ones can last for 4000 hrs if they are well made and treated well. Alternatively they can crack within a couple of hundred hours.
I sold an aircraft with good oil pressure, good compressions and spotless oil - within 200 hours it had no compression and burnt 2 lt an hour. When opened up it was tired, very tired. But if you give an aircooled engine immediate high power and run it hard with little oil surprising enough it wears - quickly.....
Blanket 'rules' on time or hours are not going to represent the actual condition of the engine - careful maintenance and inspection will.